Radial steam-turbine.



0. A. W|BERG- RADIAL STEAM TURBINE.

APPLICATION FILED JAN. 15. 19H.

1,223,914 Patented Apr. 24, 1917.

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Fig. l. "1' Tn l? m2 WM h if l m e a a' 22? la' ifid b :f 9 a? a7' g A.WIBERG. RADIAL STEAM TURBINE. APPLICATION FILED IAN. I5, ISI?.

Puentcd Apr 24, HN?.

l' I f changes as correspond to the workin OSCAR ANTON WIBERG, 0FFINSPONG, SWEDEN.

RADIAL STEAM-TURBINE.

Specification of Letters Patent. Patented Apr, 241; 191K,

Application led January 15, 1917. Serial No. 142,525.

To all whom t may concern:

Be it known that I, OSCAR ANTON WI- BERG, a subject of the King ofSweden, residing at Finspong, Sweden, have invented certain new anduseful Improvements in Radial Steam-Turbines, of which the following isa specification.

The present invention relates to radial flow elastic fluid turbines andspecifically to that type having a system of blades through which theymotive fluid flows radially outward, and a second system of bladessurrounding the first through which the motive fluid flows axially, theformer system being composed of blade carrying members that rotate inopposite directions, and the latter system of stationary fluid directingmeans and blades coperating therewith, which blades also rotate inopposite directions with those of the radial flow system. In suchturbines the stationary blades or fluid directing devices for the axialflow portion have been rigidly and directly attached to the casing or toseparate rings or supports rigidly secured to the casing.

This rigid arrangement of the stationary blades is open to certainobjections; viz., that it requires initially an. accurate centering ofthe rotor and casing with respect to each other which cannot bemaintained during the repeated changes of temperature due to .widevariations in.` load and to such and non-working periods of the turbine.wing to the difficulty of maintaining the accurate centering of thecoperating parts under the conditions specified, it has been foundnecessary' to provide relatively large clearances, especially in aradial direction between the relatively rotating parts of the axial flowsystem as, for example, between the' outer ends of the rotating bladesand the-adjacent part of the turbine casing.

In this connection it should be borne in mind that the outer casing isrelatively cold as itl delivers the exhaust directly into the condenser,and henceunder normal conditions has a substantially constanttemperature. The rotors receive high pressure high temperature fluid attheir center and d1scharge it outwardly, and hence there is a gradualfall in temperature from the inside out. Since the* load on a turbinevaries widely at times it follows that the temperatures in differentparts thereof vary with said changes and the more abrmupt these changesare the more danger there is of distortion, accompanied by rubbing ofthe parts or enlargement of the clearances, or both, in different partsof the turbine.

The object of the present invention is to overcome the objections abovenoted, and to provide a supporting arrangement for the stationary fluiddirecting means which is unaected, in so far as changes in clearancesare concerned, by variations in temperature of the motive fluid wherebythe initial clearances ma be reduced and the leakage of motive fluid andconsequent loss of power on the one hand, and frictional engagement orrubbing of the parts on the other, avoided.

In carrying out my invention the stationary fluid directing means orblades instead of being rigidly attached to the turbine casing, asbefore, are attached to a ring or member which is supported by theturbine casing in such manner that it and the casing may freely expandand contract without the movements of one causing'any displacement ordistortion of the other. In other words, the support for the fluiddirecting means will change its diameter to the same, or substantiallythev same, degree as the rotor, and in substantially the sameperiod oftime, with the result of maintaining the blade clearances substantiallyconstant in amount at all times. p

The means employed to support the member or ring from the turbine casingcan be made in a variety of ways, the essential feature being to allowthe member to have certain amount of movement perpendicular to theturbine axis, but restrainl it against lateral movement. In other Words,expansions and contractions in all radial directions should be uniformand unrestrained so that the ring will maintain its central position atvall times.

In the accompanying drawings, Figure l is a longitudinal quarter sectionof a turbine illustrating one form of the invention; Fig. 2 is asectional view of a portion of the same on a larger scale; Fig. 3 is acrosssection of a modified form of the invention; Fig. 4 is an axialsection of a further modiication wherein an expansion ring is employed,and Fig. 5 is an axial sectional view of a further modification.

a designates the turbine casingand b and 0 two shafts rotating in'opposite directions andv carrying the turbine disks d and erespectively, said casing being divided in an axial plane as is usual insuch machines. On the outer sides of the disks are concentric packingrings d and e extending between which are similar rings (Z2 and e2carried by flat plates mounted in the turbine casing. The purpose ofthis arrangement is to provide a means. for balancing the end thrust onthe disks, said packing rings serving to reduce the leakage. Motivefluid is admitted to the rotor lthrough'chests a from which it flows-through suitable passages a2 in the chests and a3 in the disks to theinner` blades of the radial flow system. Mounted on the disks areaxially extending blades f and g arranged in concentric rows and formingthe radial flow portion or system of the turbine. The disks are alsoprovided with radially extending blades la, and i which form a part ofthe axial flow portion or system of the turbine. Cooperating with theblades 71, and z' are stationary fluid directing devices lc and Z of anysuitable design which are mounted on an annular member or ring m;

The inner ends of the directing'blades are secured in any suitablemanner 'to rings Z and 7c that closely surround these portions of therotors carrying the radial flow blade system and serve to preventleakage of motive fluid at this point. The ring m is substantiallyV-shaped in cross section and has two outwardly curved surfaces m and'mfg which direct the motive fluid from the radial flow system into thestationary blades of the axial flow system. The purpose of the curvedsurfaces is to avoid shocks and eddies in the motive fluid and togradually 2 this is attained by the following means:

Projecting inside the turbine casing is a ring, flange, or rib r whichis suitably faced off on opposite sides and is supported from the casingby the studs or projections p. The purpose of using these projections asdistinguished from a complete annulus is two-fold, it permits of anequalization of the pressures of the motive fluid exhausting on oppositesides and also permits of access to the securing means. The periphery ofthe central part of the ring is provided with a groove, the side wallsof which engage the faced portion or surfaces of the ring r and are freeto slide radially thereon under temperature changes. Either as anadditional support, or as a sole support, as requirements dictate, areradial pins n of which a plu-I rality are provided. There should be atleast three of these pins and spaced equidistant. They serve to centerthe ring and also to guide it when moved in response to temperaturechanges. The pins may be xed either in the blade carrying ring m or inthe stationary part or parts r as desired, or they may be looselyarranged in both and provided with cross pins o to allow of only acertain limited longitudinal displacement. It is obvious that the pinsfn. may be replaced by radial guiding devices of any other form, forinstance, dove-tail shaped projections protruding from one part andengaging correspondingly shaped projections extending from the otherpart. These pins also serve as a means to prevent the ring from turningdue to .the action of the motive fluid flowing through-the guiding ordirecting blades. 'Owing to the fact that the flow of motive fluid isequally divided left and right the axial anced.

It is unnecessary for the guiding devices themselves to extend radially,as it is only essential thatthey guide the blade ring in a directionperpendicular to` the shaft axis. For instance, the arrangement shown inFig. 3 may be employed wherein m represents the deflecting and bladecarrying ring as before and s bars or links of suitable width havingenlarged ends which are seated in sockets in the ring and in the turbinecasing or connected parts respectively. By arranging the bars or linksas shown the-ring m can freely expand and contract, but is always heldin a central position with respect to the rotor axis. Y

In Fig. l is shown a modification wherein an expansion ring t isprovided which`is, or may be, slightly conical in shape. Its ends areenlarged to form circular anchoring devices which are seated on the onehand in a socket formed in a suitable part of the ring m, and on theother hand in a socket in a ring t that is located in the turbine casingand secured by a calking strip t2. If

ythrust on the ring is baldesired, the ring may be slotted as at t3.

' surfaces on the two rotors.

mascia the ring 7' which is supported by projections p from the turbinecasing. The bridges should be relatively thin and long in the directionof the axis of the turbine so as to give the desired elasticity.

By means of the arrangement above described I am able to definitely andexactly center the blade carrying ring m relative to the rotating parts,and said ring will always remain in its central and proper positionregardless of the expansions and contractions of the turbine casing. ltis thus possible to reduce to a small value the radial clearances,especially those between the outerl ends of the blades l1. and 'L' andthe ring m, and also those between the rings at the inner ends of theguide blades and the coperating The clearances referred to are indicatedat u and a in Fig. 4.

I have illustrated a certain construction or arrangement of parts hereinwhereby the motive fluid exhausting from the radial flow system iscaused to decrease its residual velocity before entering the blades ofthe axial flow system. This is not claimed herein as it forms thesubject matter of my applicaiin Serial No. 142,526, filed January 24,

lln accordance with the provisions of the patent statutes, l havedescribed the principle of operation of my invention, together with theapparatus which l now consider to represent the best embodiment thereof;but l desire to have it understood that the apparatus shown is onlyillustrative, and that the invention can be carried out by other means.

What l claim as new and desire to secure I by Letters Patent of theUnited States, is

l. An elastic fluid turbine comprising a radial flow blade system, anaxial flow blade system, stationary directing means which receive thefluid exhausting from the first system and deliver it to the axial flowsystem, and an inclosing casing` in combination with means forsupporting the stationary directing means from said casing which permitthe casing and means to expand and contract independently.

2. An elastic fluid turbine comprising a radial flow blade system, anaxial flow blade system, stationary directing means which receive thefluid exhausting from the first system and deliver it to the axial flowsystem,

and an inclosing casing, in combination with means supported by thecasing and attached to said stationary fluid directing means whichpermit the casing and directing means to'expand and contractindependently and revent relative axial movement of the casingand saiddirecting means. v

3. `An elastic fluid turbine comprising a radial flow blade system, anaxial flow blade system, stationary directing means which rechanging thecentral position of said memy ber.

4. An elastic fluidy turbine comprising a radial flow blade system, anaxial flow blade system, stationary directing means which receive thefluid exhausting from the first system and deliver it to the axial flowsystem, and an inclosing casing, in combination with an ann lar memberwhich carries rows of fluid dlrecting means on opposite sides and has adeflector between, and means which are attached to the member and alsoto the casing which permit one of said parts to expand and contractindependently of the other.

5. An elastic fluid turbine comprising a radial flow blade system, anaxial flow blade system, stationary directing means which receive' thefluid exhausting from the first system and deliver it to the axial flowsystem, and an inclosing casing, in combination with a ring to which thedirecting means are rigidly attached, means for supporting the ring fromthe casing which permits the ring and casing to expand and contractindependently, and means for holding the ring concentric with theturbine axis when said expansions and contractions take place.

6. An elastic fluid turbine comprising a radial flow blade system, anaxial flow blade system, stationary directing means which receive thefluid exhausting from the first system and deliver it to the axial flowsystem, and an inclosing casing, in combination with a ring to which thefluid directing means are rigidly attached in sets, rings which unitethe inner ends of said sets and occupy positions in close proximity tothe rotors of said systems, and means for supporting the directing meansfrom the casing which permits them to freely expand and contractindependently but prevents relative axial movement. 1

7. An elastic Huid turbine comprising a radial flow blade system, anaxial flow blade system, stationary directing means which receive thefluid exhausting from the first system and deliver it to the axial Howsystem, and an inclosing casing, in combination with a ring to which thefluid directing means are rigidly attached, a support for the ring whichis carried bythe casing, and guiding means between the support and ringwhich permit one to slide on the other, and means to center the ringwith respect to the blade system. l

8. An elastic fiuid turbine comprising a loo radial flow blade system,an axial flow blade the projecting means and the ring to center 13system, stationary directing means which rethe latter.

ceive the Huid exhausting from the first sys- In testimony whereof Iafiix my signature tem and dleliver it to the axialbflow system, inpresence of two Witnesses.

and an inc osing casing, in com ination with a ring to which the fluiddirecting means OSCAR ANTON WIBERG' are rigidly attached, meansprojecting in- Witnesses:

Wardly from the casing to form a support GUSTAF JANssoN, for the ring,and means that pass through FRITZ E. HALLIN.

